Zigzag sewing mchine having operating means for adjusting the stitch width and the position of the stitching field



1961 F. GEGAUF 3,012,528

ZIGZAG SEWING MACHINE HAVING OPERATING MEANS FOR ADJUSTING THE STITCHWIDTH AND THE POSITION OF THE STITCHING FIELD 2. Sheets-Sheet 1 FiledJuly 17, 1959 IHH lllll INVENTOR- FRITZ GEGAUF BY Dec. 12, 1961' F.GEGAUF 3,012,528

ZIGZAG sEwING MACHINE HAVING OPERATING MEANS FOR ADJUSTING THE sTITcHWIDTH AND THE POSITION OF THE sTITcHING FIELD Filed July 17, 1959 2Sheets-Sheet 2 Utcd States Patent 3 012,528 ZIGZAG SEWING MAHINE HAVINGOPERATING MEANS FOR ADJUSTING THE STITCH WIDTH AND THE POSITION OF THESTITCHING FIELD Fritz Gegauf, Steckborn, Switzerland, assignor to F rrtzGegauf Aktiengesellschaft Bernina-Nahmaschinenfabrik, Steckboru,Switzerland Filed July 17, 1959, Ser. No. 827,888 Claims priority,application Switzerland July 17 1958 4 Claims. (Cl. 112-158) Inheretofore known zigzag sewing machines the operating means forregulating the stitch width and the position of the stitching field,that is the extent for which the central alignment of the sewingstitches is shifted to the right and left, are arranged at the frontwall of the upper sewing machine arm each on a separate axis or alsocoaxially. The borings in which are arranged the axles for suchoperating means must be worked separately in the production cycle of thesewing machine with corresponding waste of time and raise of the costs.The mounting of such operating means moreover is complicated and veryexpensive owing to the position of their borings with respect to thezigzag mechanism and in view of the 'required bearing and connectingelements.

It is a prime object of the present invention to reduce the cost ofmanufacture and assembly of a sewing machine by arranging at least oneof said operating means for the stitch width and for the position of thestitching field on a common axle necessarily present for another memberof the machine.

According to the present invention this object is attained by arrangingone or the other of said operating means or both coaxially with respectto each other on the driving shaft for the zigzag mechanism of themachine.

Other features and advantages of the invention will become apparent fromthe following description of a preferred embodiment thereof, in whichreference will be made to the accompanying diagrammatical drawings, inwhich:

FIGURE 1 is a partial elevational view of a zigzag sewing machineshowing the operating means for adjusting the stitch width, the positionof the stitching field and the stitch length.

FIGURE 2 is a view similar to that of FIGURE 1 but with the front wallbroken away in order to show the drive for the zigzag mechanism.

FIGURE 3 is a cross-sectional view taken along the line I-I in FIGURE 2,and showing the operating means for the stitch width and for theposition of the stitching field, and

FIGURE 4 is a horizontal sectional view of FIGURE 2. Referring to thedrawing reference numeral 1 designates I the L-shaped upperarm of asewing machine having a removable cover 2. Reference numeral 3designates the base plate of the sewing machine and reference 4 thedrive wheel of the machine. At the front wall of the arm 1 there arearranged: the operating member 5 for adjusting the stitch width and itsgraduation 6, the operating member 7 for adjusting the position of thestitching field with an arrow 8 and a lever 9 for adjusting the stitchlength. An abutting screw 10 arranged below the drive wheel 4 serves tolimit the stitch length. The drive wheel 4 is releasably connected in aknown and not represented manner with the main drive shaft 11 arrangedin the arm 1. A driving gear 12 for the zigzag mechanism is rigidlymounted by means of a screw 13 on the shaft 11. A driven gear 14revolving at one half of the speed of main shaft 11 forms one part withthe zigzag eccentric 15 and is loosely mounted on a supporting axle 16.The eccentric 15 abuts a set ring 17 secured to the axis 16 ice 7 bymeans of a screw 1*8 while the gear 14 abuts with its side opposite theeccentric a groove or star segment 19 secured to the axle 16 by means ofa screw 20. The eccentric 15 is enclosed by a fork '21 rigidly connected'by means of a screw 23 with its tilting axle 22 mounted in an eye 24 ofthe arm 1. The pendulum movement imparted to the fork 21 by theeccentric 15 is transmitted to a swinging lever 25 secured to the axle22 by means of a screw 26.

A stitch width link 27 is tiltably mounted in lever 25 through a tap 28.The slide member 29 of the link 27 is connected on the one hand by anarm 30 with the not represented needle bar link and thus with the needleand on the other hand by an attachment 31 and through a screw 32 isarticulated to the lever 33 for adjusting the stitch width. Theadjusting lever 33 has a long hub 34 by means of which it is pivotallymounted in a bushing 56 secured to the arm 1 by means of a screw 35. The

of a tap 40. The position of the segment 19 having three grooves forleft position L, middle position M and right position R is secured by apin 41 arranged in a boring in the arm 1 and engaging under the actionof a spring 42 one of the grooves depending of the position of thesegment 19.

In operation the drive wheel 4 entrains the shaft 11 and imparts throughthe helically geared wheel pair 12, 14, the zigzag eccentric 15 and thefork 21 a pendulum movement to the link 27. If the operating member 5for adjusting the stitch width, which is mounted on axle 16, isdisplaced to a position departing from the zero position and indicatedon the graduation, the adjusting lever 33 moves the slide member 29 ofthe link 27 to a corresponding position spaced from the zero position.The army 30 pulls the needle to a greater or to a smaller needledeflection or amplitude. The modification of the needle amplitude mayalso be effected during the sewing operation. In order to modify theposition of the stitching field, i.e. in order to shift the stitches tothe right or the left of the normal needle path, the operating member 7also mounted on the same axle 1'6 and provided with the arrow 8 ispivoted in such manner that the arrow is directed to the left, to themiddle or to the right, whereby the stitching field position iscorrespondingly adjusted. Thereby the pin 41 engages one of the groovesL, M, R of segment 19 and secures the desired position. The member 39 isarticulated as well to the segment 19 as also to the link 27 which inturn is articulated to the swinging lever 25. The member 39 displacesthe zero position of the link 27 in accordance with the adjustment tothe left or to the right into the desired position and thus modifies thestitch field position of the needle.

The illustrated embodiment may of course be modified by arranging onlythe operating member for the stitch width or only the operating memberfor the stitching field position on the driving shaft of the zigzagmechanism without departing from the scope of the invention as definedin the claims.

I claim:

1. In a zig-zag mechanism for a sewing machine ineluding an oscillatableslide link, a slide slidable on said link and connectable to a needlebar to shift the bar during its reciprocation, the improvementcomprising a supporting axle, a driving member rotatable on saidsupporting axle, means connected to said driving member and said slidelink for oscillating said link, a first operating member rotatable onsaid driving axle connected to said slide and rotatable to shift theposition of said slide to vary the stitch width, a second operatingmember afiixed to said supporting axle to rotate said axle, and means onsaid supporting axle connected to said slide link to change the positionof said slide link upon movement of said second operating member andsaid axle to vary the field position.

2. In a Zig-zag mechanism according to claim 1, wherein said firstoperating member includes a sleeve rotatable on said supporting axle,and a knob affixed to said sleeve.

3. In a Zig-zag mechanism according to claim 1, wherein said secondoperating member includes a knob connected to one end of said supportnigaxle.

4. In a zig-zag mechanism according to claim 1, wherein said drivingmember is a sleeve having a gear portion at one end and an eccentricportion at the opposite end connected to said slide link for oscillatingsaid slide link.

References Cited in the file of this patent UNITED STATES PATENTS1,997,411 Eames Apr. 9, 1935 2,047,754 Tiesler July 14, 1936 2,653,557Casas-Robert et al Sept. 29, 1953 2,757,626 Fujita Aug. 7, 1956 FOREIGNPATENTS 792,784 Great Britain Apr. 2, 1958

